Brake mechanism



May 8, 1928.

1,668,877 R. D. sTRouP BRAKE MECHANI SM Filed July 26. 1924 5Sheets-Sheet 1 76.7). Sz ro op May 8, 1928. 1,668,877

R. D. STROUP BRAKE MECHANI SM Fil-ed July 26. 1924 3 Sheets-Sheet 2 102r1 J 100 ,101 f10 14 May 8, 1928. 1,668,877

R. D. STROUP BRAKE MECHANI SM Syvum do@ D. SZW-04,919

Patented May 8, 198218.

ROBERT D. STROUP, OF MARFRAiN'GE, WEST VIRGINIA.

BRAKE MECHANISM. f

Application led p July 26,

This invention relates to brakel mechanism and more particularly to suchmechanism wherein the brake is positively locked in operative positionso that it cannot be released b chance or accident runtil such releaseis `rected by the engineer or other operator under` whose control themechanism is placed.`

Attempts `have. been made in the prior art to secure a positively lockedbrake. It has been sought primarily to insure positive braking action toprevent, for example, runaway trains, due to failure of air, pressure inair pressure operated brakes, or due to a failure of the electriccircuit in electrically operated brakes, or for other reasons. It is ofcourse obvious that in `fluid pressure voperated or in electricallyoperated brakes, if at any time there is a failure either of the fluidpressure or of the electric current as the case may be, the brakes mustcease functioning. Furthermore when cars, for example freight cars areshifted from a train onto a siding, leakage of air in air pressureoperated brakes, will gradually unset the brakes, so that `a carstanding on a grade will run away. But the devices of the rior artreferred to above, which have soug tto overcome these difficulties werethemselves so complicated and costly that their use was impracticable,and usually theseV devices have proved inoperative under the strain ofusual operating conditions. One of the chief reasons for this was thatsuch prior art devices required double setsof mechanism, including aircylinders, pipe lines, etc.. `that is one set for locking the brakes andanother set for unlocking them,Y The changes thus caused in such devicesmade them prohibitive.

In my prior applications serially numbered 853,751; 663,360; and 685,408and filed July V25, 1923; September 18, 1923; and Jani nary 10,1924,respectively, I have set forth certain brake mechanism designed toovercome these difliculties and to supply simple and certain structuresfor locking the brakes and releasing them which Ashall always be underthe control of the engineer, and positive in operation, withemergencyreleasing means. This application presents further improvementson that mechanism.

Many advantages Will appear from the following more detailed descriptiontaken in conjunction with the accompanying drawings wherein tliereis`shown by wayof illustrated Wit 1924. Serial No. 728,360.

ter of the device; in Figure 4, a detail plan 4 vievv ofthe holdingbarwith the improved releasing bar and associated parts; in Figure 5, adetail view in elevation of the parts shownin Figureli; in Figure 6, afragmentary View ofthe releasing bar in operative position; in Figure7,.a fragmentary View of the releasing dog and releasing bar thereleasing bar having returned to its normal position; in Figure 8, adetail of the holding bar,` locking'pavvl, and releasing dog in relativeposition; in Figure 9, a fragmentary perspective view of the end of theholding bar; in Figure 10, an end view of the assembled mechanism; inFigure 11, a detail partly in section of the locking and releasingpawls, in Figure 12, an end view of the locking pawl and releasing pawlcarried by the same; in Figurel, a erspective detail of the releasingbar; in igure 14, a p erspective detail ofthe releasing dog andassociated parts; and in Figure 15, a perspective detail of thereleasing dog. p

' But it will beiunderstood that thedescription and drawings are to kbetaken as illustrative only, and not by way of limitation,

`since various changes may be made in the devices as illustrated anddescribed, by those skilled` in the art to which this inventionappertains, Without departing from the spirit and the scope ofthisinvention. y

`:[ngeneral it will be seen that this invention comprises exceedinglysimple means for positively lockingand releasing brakes which can` beappliedto brakes of all kinds Whether operated manually, electrically,`or byyflufidpressure, for example. air, steam, etc. For purposes ofillustration however the device will be shown in use with air pressurebrakes.

ln its more` fundamental aspect the invention set's forth means operatedby the existing `air brake cylinder to lock the brake in operative`position after it has been set, and means for releasing the lockingmechanism also ,preferablyJoperated by the same air cylinder. i As aresult it is possible to make use of practically the present equipmenton trains with but slight modification. As4 set forth above, thisinvention ma be applied td any typ of' brake, although it is illusanLair brake. In will); adaptalll) tion to other forms of brakes, all thatis required-is that there shall be a holding bar or its equivalent whichis operated bythe brake operating mechanism in its usual course ofoperation. This bar is then locked by the locking means, and may besubse-V quently released by the releasing means. It is innn aterial forthe purposes of the present invention whetherthe holding bar or itsequivalent is operated by tluid pressure, electrically or otherwise. ltsapplication to any of these brakes will be obvious from the detaileddescription.

Referring more particularly to the drawings thereris shown bv way ofillustration, the conventional brake cylinder 1 within whichreciprocates the usual piston 2, ac-' tuating piston rod 3, whichextends through the cylinder head 4. In this modification of theinvention, the usual cylinder head is replaced by one similar to thatillustrated in accordance with the principles of this invention. Thiscylinder head 4 thus carries a small cylindrical member 5, through theopening of which the piston rod 3 extends. Upon this member 5, andpreferably, there are two strips 7, 7, which may be made integral withthe member 5 and preferably are so made, those strips acting to form achannel within which thev holding bar reciprocates.

The holding bar 10 carries a rack 11 on its upper face which extendsfrom its inner end of the bar for about half of its length, more orless, although the' exactdistance is governed b other .considerations orrequirements, or example the minimum distance of operation before brakeaction shall begin. On its outer end 14, the bar 10 carries a dependingear provided with an aperture or opening through which openingr thebrake red link passes to the brake rod, and serves to transmit themotion from the iston rod to the brake rod, whereby the iirake isoperated. Due to the bifurcated ear 22 of the link, by means of which itis connected to the brake rod, when the bar 10 has advanced to itslocked operative position, the link cannot move inwardly, but itsmovement in that direction is obviously limited by the ear 15. One ofthe sides of the bar 10 is cut away to form a groove 100 which isbeveled at 101 to the side of the bar. This groove is made to receivethe releasing pawl described below.

This groove 100 with its beveled end 101 may extend for the entirelength of the rack 11 on the bar 10, or for only a ortion thereof. Andwhile a groove of 't iis character has been used-in actual practice,this groove is preferably used in the following modification. Along itsinner portion 102, a series of shoulders 103 are formed. From theseshoulders, teeth 104 extend diagonally across the groove to its outsideedge, rising at `ates.

their outer ends so that they are higher at at the outer, ends than atVthe inner ends. There will generally be as many teeth as there areshoulders 103, and the number of cach may bc varied at will, dependingon the control desired. Fivey have been found in practice to give,etlicient results. These shoulders 103 andVV teeth 104 will behereinafter referred to as emergency points and their function willy befully described below. i'

A cover plate serves to form a housing for the locking pawl 40 and thereleasing pawl 50;' For this purpose it is provided with a verticallyextending hood 3l Vwhich has vertical sides 32and 33 forming the channelwithin which the locking pawl'oper- The side 83 is formed'as shown at 34to provide a bearing surface for the rocking arm 73. The remainder ofthe channel within which the locking pawl operates, is formed from ablock provided on its upper side or face with thev lower half of thebearing surface for the rocking arm. In the preferred form, the block 35is integral with the cylinder head 4. The cylindrical niember 5 of thecylinder head carries an opening 3T through which the bar 10 moves. Thelower end of the channel referred to above is thus open to the bar 10 soAthat the locking pawl 40 may contact with the upper face of the bar 10.

This locking pawl 40 is cut away as shown at 41 to form an opening forthe purposes described below. The pawl is beveled at its lower end 42 sothat it can coact with the teeth of the rack bar 10. At one side of thepawl, a longitudinal channel 43 is cut to receive the releasing pa wl50.

The` releasing pawl is pivoted at 51 for transverse movement in thechannel 43, the arm 35 adjacent to this pawl being cut away to allowsuch movement. The pawl 50 is spring pressed as shown at 54 so that inits normal. position the releasing pawl presses against the side 21 ofthe rack bar 10, but outside of the groove referred to above. In itsoperative position however, the pawl 50 rides in the groove 100.

The rocking arm 73 carries a lug 74 rigidly attachedthereto as at 75.This lug extends within the opening 41 adjacent to the upper partthereof, so that when the roel;- ing arm is rocked countercloclrwise onits bearings, the lug serves to raise the locking Vpawl free of theYraclr on the ba r 10. In order to retain the locking pawl in contactwith the teeth of the holding' bar 10, a block 44 held in place in anydesired manner is reposed against the action of a spring 45, actingagainst this block and the lower edge of the opening or passageway 41,serves to press the locking pawl down against the teeth of the bar 10.The spring 45 may be retained in proper position by means of they Ulijail) outer or free en dot which is attached achain or equivalent device78, the latter being adapted to be wound up or pulled over by a verticalhand brake stall' similar to that now in use on hand brakes. Thisarm 77and attendant parts just referred to is purely optional, their purposebeing to supply means whereby the brake may .beireleased and restored byhand. It is obvious that whenthe element 78 is pulled over or wound upby the operation of the hand wheel etc., not shown, the rocking arm 73will beoperated to release the locking pawl 'so that the brake rod mayreturn to its normal position under the action of the spring. y

The releasing rod which forms a further feature of this specificationwill now described. l The releasing bar proper comprises a bar 80 cutalong its lower edge to form a series of rather large, widely separatedteeth 81, havingV corresponding notches 82. These notches have paralleleut sides 83 formed at s an angle to the'lower edge `oit the bar 80,

and rising from this lower edge totheir greatest point of cut at 84wherethey are practically horizontal, and then dropping straight down to thebottom edge again as shown at 85.` Thesediagonally cutredges Y 83 have acorrespondingly cut edge 86 at the (ill outer end of the bar 80asshownat 87 The inner end of the bar 80 is cut to form a shoulder 88with a beveledrlower edge 89 and a beveled upper portion 90. The holdingbar 10 isprovided `with a series of lugs 91 correspondingito the notchesor. recesses 82, these lugs having diagonally cutmsides 92, andhorizontal upper faces 93.k The side of the holding bar`10 is further.cut away to form a shoulder 94; against which the edge 86 of thereleasing barrests. There may be any desired number of these recesses 82*and corresponding lugs 91; for example three have proved ample inactual operation.

The `holding bar 10 further `carries a spring pressed plunger 11() heldin itsiouterniostposition by a Vspring 111` `wound about the reducedportion 112 of the plunger, and pressing at one endagainst the inner.wall 113 ot the opening 114in the holding bar which forms a housing forthis plunger 110. The other end of the spring rests against the shoulder115 formed on the plunger. A pin 116 acting against shoulder 117 on theplunger limits the outermost movement of the plunger due to the actionof the spring 111.v The plunger is cut away at 118 to form the shoulder117 and also so y that the plunger during its reciprocating movementwill clear the pin 116. The plunger 110 further carries a dog 119 havinga bifurcated ear 120 `pivoted on the ear 121 of `the plunger 110.` Thisdog 119. is formed with an ear122 which rests against the shoulder 88formed. on the releasing bar 801The` holding bar 10 is cut away at itsend 123 which contains thefhousing for the plunger to form arcuate faces124 and 125, one of the facessuch as 124 being more deeply cut as shownat 126 to reeeivethe lug 127 carried by the corresponding bifurcation ofthe biurcated ear 120. It will he apparent from the association of partswhich have just been described and as further illustrated in,particularly Figure t'of the drawings, when the plunger 110 movesinwardly against the aetion'ot the spring ]11,.the ear122 of the 'dog119 resting against `the shoulder `88 of the releasing bar 8O moves thelatter lin the same direction. `Due totheicooperationof the recesses ornotches 82 with. the llugs 91,

asthe releasing bar moves in ythe direction indicated, it is raised asshown in Figure 6 and as further illustrated in Figure 11 in beingraised, it raises the locking pawl 40 which extends above it, up abovethe rack 11 on the bar 10 thus releasing `the locking mechanism. At thesame `1 time, `the releasing pawl 50 will move into the` groove. 100 andthus maintain the locking pawlin `its position outer' contact with theraclr 11. As the plunger continues its inward movement, the lug 127 onthe ear 120 movi-ng along the larcuate face 124 forces the dog 119upwardly until thel ear. 122 is clear of the shoulder 88.` As soon `asthis point `is reached,tlie releasing bar 80' drops back under theinfluence of itsown weight to its normal position. C However if desired,a spring may be used to return the-ban 80 to its normal position afterit has been released weight oi the parts, the pawl 40 may be muchsimplified Aby the omission et" the spring 15.with `its attendant parts.It` will still retain the openingietl which receives the lug 74 of therocking arm 73. The pawl 4() in any event may/terminate in la singlebeveled edge 42 or 4it may have several teeth 42 formed thereon whichserveito ive a better grip on the bar 10. Thepaw el() also carries thelongitudinal channel 43 in which the releasing pawl 50 is pivoted bymeans of the pivot openings 51. 'l'he recess 54- forms `a seat for thespring 54e which presses against the upper end oi' the pawl 50. i

When the parts have been assen'ibled as set forth above, it is ready ioruse and operates as follows. As soon as the engineer applies the brakes.the piston rod moves outwardly and by means of the brake rod, the brakesare brought into operative position. At the same time, thepiston movesagainst the outer end of the plunger 110 and after orcing the latter inagainst the action of the spring 111, carries the entire holding bar outuntil, when the movement has been sufiicient, the teeth of the rack 11on the bar 10 engage the pawl 410, which then locks the rack and baragainst in\vard movement. NOW at this time regardless of what happenseither to the air line, or Within the'rcylinder, the brake rod ispositively locked in position, so that the brakes cannot be releaseduntil the engineer under ivhose direction the entire mechanism isplaced.` desires to do so. In this Way it will be seen that although theair. pressure in the air line may vary, or decrease diie to leakage, thebrakes are positively locked so that the train cannot move until suolimovement` is desiredl In this connection attention is called to the factthat, generally, the brake rod, or piston rod,1nust move a minimumdistance (say about three and one-half inches) tor what is termedleakage groove, before the brake shall begin to operate. Advantage is:taken of this fact in the present invention. The rack bar is not toothedin that part that will ride under the locking pavvl during the initialtravel of the bar 10 under that pawl, that is through the distancereferred to above.` Consequently, at this time, when the brakes arebeing set, While the plunger 110 Will move in and raise the releasingbar S0 which Will in turn raise the paivl 4:0, since the bar 10 is nottoothed at this point, the paWl 40 Will return to its normal position,and as soon as the full movement of the plunger has been made, thereleasing bar 80 will likewise return to its normal position. Themovement of the pawl 40 further results from the. fact that the groove100 starts at about the same point on the bar 10 as does the rack 11.`When the brakes are however once set as just described, the piston andpiston rod may return to their normal position and do so under theaction of the spring described above, and the plunger 110 also returnsto its normal posi,- tion.

Thon however it is desired to release the brakes and allow them to ceasetheir braking action, the engineer once more applies the brake but it isonly necessary to move the piston a small distance. that is sutlicient ito operate the plunger 110 and move the latter inwardly against theaction of the spring 111. That is. regardless ot' the pressure that hasbeen used in setting the brakes, in order to unset them a minimumpressure only .is required. When this is done, the releasing bar 80 israised along the lugs 91 by the dog 119, until Vthe locking pawl islifted out ot engagement with the rack 11. As soon as this has happenedthe releasing paivl moves into the groove 100 and maintains the lockingpawl 40 above the rack 11. The plunger continues its movement until thereleasing bar 80 isdisengaged from the dog 119 whereupon the releasingbar immediately drops back to its normal position. At the same time, theholding bar 10 and attendant parts are free to move back to their normalposition, the paWl 50 riding in the groove 100 and still maintaining thelocking pawl 40 out of operative engagement with the rack'll. If theVmovement continues as it does in normal operation, when the rack bar 10has gained its normal position, the pawl 50 will have been 'forced outof the groove v100 by the Wall 101, and will drop down to itsinoperative position, allowing the paivl 40 to tall against the rack bar10 but at a point now where there are vno teeth. rhe parts will thushave returned to their normal inoperative position, and will be readyfor a further application of the brakes when desired. Since themovements Which have just been described take place immediately, thereis no delay of any moment before the parts reach their normal position.i

Should it become necessary at any time after the brakes have beenreleased as just described above. and before theyhave regained theirnormal position, to apply the brakes, this may be done at once. For thispurpose the emergency oints referred to above have been supplier. Ifat'any moment after the locking pavvl has been released, and before theparts have returned to their normal position, it is desired to apply thebrakes, the engineer starts to operate them without Waiting for theparts to assume their normal position, by applying the desired pressure.The inward movement of the bar 10 will reverseitself, and begin to moveoutwardly. For the time being however, were it not for the emergencypoints, the releasing pavvl 50 would continue to ride in the groove 100and prevent the locking pawl 40 from coming into locking engagelnentwith the rack 11. The locking pawl musttherefore be restored to itscontact with the rack 11 at once, and this is the function of theemergency points. As soon as the bar 10 reverses its direction ofmovement as just described above, the releasing pawl momentarily ridesin the groove 100 unt-il it reaches one of the shoulders 103. the.

shoulder reached depending on the moment Y memoir secured .at` any timeduring the releasing operation, and will be more or less con,-4

trolled by the number of emergencypoints used. i i Sometimes it isdesired to release and rcstorethe brake by hand, particularly when a carhas been switched oil' ot a train 0i' line otears. This is accomplishedby winding up or pulling over the chain or equva,

.lent device 78 as described above.,V I'Vh'en this isl done, the rockingarm 'evill raise the pawl 40 out ot engagement with the rack lll ksothat the bar 10,-a.nd consequently the brake rod may return to itsnormal position under the action of its spring.

At times it is desirable to use this inveiition without the releasingpawl, and insuch cases the latter with its attendant parts may be easilyeliminated or removed. Such omission allowsone tok drop from a higherpressure to a lower one without first going through the releasingroperation. This rosults from the fact that when the brakes have oncebeen set and locked, when no releasing pawl 50 is used, all that isnecessary is that the engineer should move the brake to the pressurethat he desires to apply. As the plunger 110 ispressed inwardly againstits spring 111, the releasing bar 8() will unlock the locking pawl byraising the latter above the rack 11. As soon as this happens,

, the throw"7 on the brakes will tend to restore the parts to theirnormal position. This throwing action is due to the normal resistance ofthe brakes. As soonhowever, as the brake rod and pistonrod move back toa point where the bar 10 has been locked they cannot move further. Thebar'lO becomes locked due to theifact thatafter releasing the pawl 40,the releasing bar 80 soon' reaches the point where the Vdog 119disengages the shoulder 88, and the releasing bar returns to its normalposition. locking pawl 40 thusdrops downv and locks the bar 10 at thepoint to which it has returned due to the throwing action of the brakeswhile the pawl 40 has been raised out of contact with the rack 11. Sincethe pressure on the piston` has been only partially released the lockingbar 10 cannot return due to the throwing action to anything but animmediate position, determined by the lower pressure which the engineerhas applied. In this way the brakes may be locked at any lower pressureposition.

The cover plate 30 serves to protect the workinor parts against theentrance of dirt etc., and may also be provided withoil cups etc. forlubrication of the Working parts. It is thus seen that all ofthe movingparts are contained within the cylinder.

Having thus set forth my invention, I claim: i

1. In brake mechanism, means for locking `locking means.

The

the brake against4 movement, means for releasing said locking means, andemergency means forunsetting the releasing means.`

. 2. In brake mechanism, means for holding the brake against movement,locking means operated by said brake holding means, td lock the holding`means in operative posi` tion, and releasing means to releasethesaid i`3. In brake mecl'ianisiii,.means for `holding thebi'ake againstmovement, lockingdgieans operated by said brake holding means, to

lock the holding means in operative position,`

andreleasing means to `releasethe saidlocking means comprising areciprocable bar adapted to maintain the locking means tern- Vporarilyin inoperative` position.

4. In'brake mechanism, a fluid pressure cylinder, a piston withinsaidcylinder operating under the fluid pressure in -saidcylinder, means forholding the brake in set position, locking means operated by saidpiston, to lock said holding means, and means for releasing said lockingmeans operated by said piston. i

5. In brake mechanism, a fluid pressure cylinder, a piston within saidcylinder operi ating under the fluid pressure in said cylinder, meansfor holding the brake in set position, locking means operated by saidpiston to lock said holding means, and means for releasing said lockingmeans operated by leasing said `releasing means operated by said piston.

`6. In brake mechanism, a brake, means for setting said brake inoperative position,

said piston, and emergency means or remeans operated by said settingmeans for locking said brake in any set position, means operated by saidsetting means for releasing said locking means, and `emergency means forunsetting said releasing means.L

l7. In brake mechanism, a brake, means for 1 setting lsaid brake 1noperatlve position,

means operated `by said setting means for locking said brake in any setposition, and means carried by said locking `means for releasin `thelatter.

8. In rake mechanism, a brake, means for setting said brake in operativeposition, means operated by said setting means for locking said brake inany set position, and means operated by said setting means for releasingsaid locking means.

9. In brake mechanism, a reciprocable holding bar, means for lockingsaid holding bar on initial movement thereof, means for releasing saidlocking means, and means for maintaining the locking means temporarilyin inoperative position and simultaneously placing the releasing meansin operative` position. s

10. In brake mechanism, a holding bar providedwith a rack, a pawlengaging said rack to lock saidbar against movement in tion, means forreleasing said locking means.

operative in any position of the locked brakes. e

12. In brake mechanism including means for locking the brakes operatedby means for holding the brakes in the locked position, means forreleasing said locking means.

13. In brake mechanism includingmeans for locking tho brakes in any setposition, and means for releasing said locking means, means providingfor emergency unsetting of the releasing means. c

ROBERT D. sTRoUP.

